71-43-2

Benzene is also known as benzol, benzole, coal tar naphtha, and phenyl hydride, benzene is a clear, colorless, flammable liquid made by passing coke gas through oil, which is then distilled to produce benzene and toluol. The benzene is separated from the toluol by fractional distillation. Benzene is soluble in alcohol, ether, chloroform, and glacial acetic acid, but it is insoluble in water. Benzene was used as a solvent for many photographic operations in the 19th century. In the collodion process, benzene was used to dissolve rubber to both subcoat and supercoat negatives. It was also used as a solvent for Canada balsam in the Cutting method of sealing ambrotypes and cementing lens elements. Benzene was also used as a solvent for wax, gums, resins, and amber and in particular for retouching varnishes applied to silver bromide gelatin negatives.

R45:May cause cancer.
R11:Highly Flammable.
R36/38:Irritating to eyes and skin .
R48/23/24/25:Toxic: danger of serious damage to health by prolonged exposure through inhalation, in contact with skin and if swallowed .
R65:Harmful: May cause lung damage if swallowed.
R39/23/24/25:Toxic: danger of very serious irreversible effects through inhalation, in contact with skin and if swallowed .
R23/24/25:Toxic by inhalation, in contact with skin and if swallowed .

S53:Avoid exposure-obtain special instruction before use .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S36/37:Wear suitable protective clothing and gloves .

Confirmed human carcinogen producing myeloid leukemia, Hodgkin's dsease, and lymphomas by inhalation. Experimental carcinogenic, neoplastigenic, and tumorigenic data. A human poison by inhalation. An experimental poison by skin contact, intraperitoneal, intravenous, and possibly other routes. Moderately toxic by ingestion and subcutaneous routes. A severe eye and moderate sktn irritant. Human systemic effects by inhalation and ingestion: blood changes, increased body temperature. Experimental teratogenic and reproductive effects. Human mutation data reported. A narcotic. In industry, inhalation is the primary route of chronic benzene poisoning. Poisoning by skin contact has been reported. Recent (1 987) research indicates that effects are seen at less than 1 ppm. Exposures needed to be reduced to 0.1 ppm before no toxic effects were observed. Elimination is chiefly through the lungs. A common air contaminant. heat or flame. Explodes on contact with diborane, bromine pentafluoride, permanganic acid, peroxornonosulfuric acid, and peroxodisulfuric acid. Forms sensitive, explosive mixtures with iodine pentafluoride, silver perchlorate, nitryl perchlorate, nitric acid, liquid oxygen, ozone, and arsenic pentafluoride + potassium methoxide (explodes above 30℃). Ignites on contact with sodium peroxide + water, dioxygenyl tetrafluoroborate, iodine heptafluoride, and dioxygen difluoride. Vigorous or incandescent reaction with hydrogen + Raney nickel (above 210℃), uranium hexafluoride, and bromine trifluoride. Can react vigorously with oxidzing materials, such as Cla, Cr03,02, NClO4,03, perchlorates, (ACl3 + FClO4), (H2SO4 + permanganates), K2O2(, NH4OH + acetic acid), Na2O2. Moderate explosion hazard A dangerous fire hazard when when exposed to heat or flame. Use with adequate venulation. To fight fire, use foam, CO2, dry chemical. Poisoning occurs most commonly via inhalation of the vapor, although benzene can penetrate the skin and cause poisoning. Locally, benzene has a comparatively strong irritating effect, producing erythema and burning, and, in more severe cases, edema and even blistering. Exposure to high concentrations of the vapor (3000 ppm or higher) may result from failure of equipment or spillage. Such exposure, while rare in industry, may cause acute poisoning, characterized by the narcotic action of benzene on the central nervous system. The anesthetic action of benzene is sirmlar to that of other anesthetic gases, consisting of a preluninary stage of excitation followed by depression and, if exposure is continued, death through respiratory failure. The chronic, rather than the acute, form of benzene poisoning is important in industry. It is a recognized leukemogen. There is no specific blood picture occurring in cases of chronic benzol poisoning. The bone marrow may be hypoplastic, normal, or hyperplastic, the changes reflected in the peripheral blood. Anemia, leucopenia, macrocytosis, reticulocytosis, thrombocytopenia, hgh color index, and prolonged bleeding time may be present. Cases of myeloid leukemia have been reported. For the worker, repeated blood examinations are necessary, inclulng hemoglobin determinations, white and red cell counts, and dlfferential smears. Where a worker shows a progressive drop in either red or white cells, or where the white count remains below <5000/mm3 or the red count remains below 4.0 d o n / m m 3 , on two successive monthly examinations, the worker should be immediately removed from benzene exposure. Elimination is chefly through the lungs, when fresh air is breathed. The portion that is absorbed is oxidized, and the oxidation products are combined with sulfuric and glycuronic acids and eliminated in the urine. This may be used as a lagnostic sign. Benzene has a definite cumulative action, and exposure to a relatively hgh concentration is not serious from the point of view of causing damage to the blood-forming system, provided the exposure is not repeated. In acute poisoning, the worker becomes confused and dizzy, complains of tightening of the leg muscles and of pressure over the forehead, then passes into a stage of excitement. If allowed to remain exposed, he quickly becomes stupefied and lapses into coma. In nonfatal cases, recovery is usually complete with no permanent disabhty. In chronic poisoning the onset is slow, with the symptoms vague; fatigue, headache, dizziness, nausea and loss of appetite, loss of weight, and weakness are common complaints in early cases. Later, pallor, nosebleeds, bleeding gums, menorrhagia, petechiae, and purpura may develop. There is great inlvidual variation in the signs and symptoms of chronic benzene poisoning.

LD50 orally in young adult rats: 3.8 ml/kg (Kimura)